Yes and no. I don't believe love, itself, is a choice. You either love someone or you don't. Whether you act on it or not, is where the choice part comes in.

It would be so much easier if love were a choice. Then two people could choose to fall in love regardless of whether they had chemistry or not. Just doesn't happen that way.

And yes, I believe it's possible to fall out of love with someone you don't think is a good fit, but it might take time depending on how well you accept that he/she isn't right for you. I've drove myself crazy in the past, but eventually I found peace with it and that person will always have a special spot in my heart, but I am no longer in love with him. It just sort of faded away, but took some inner work before that happened.